LAMBDA Thermal Conductivity Meter

LAMBDA is a compact, operator-friendly hot-wire instrument that facilitates a fast determination of the thermal conductivity, thermal diffusivity and specific heat capacity in a wide temperature and pressure range by means of the transient hot wire (THW) method in accordance with ASTM D7896-19.

This highly accurate device is suited for fluid analysis in the laboratory as well as in the field, including the measurement of thermal conductivity of coolants, oils, gels, or nanoparticle dispersions/nano fluids.

The LAMBDA Thermal Conductivity Meter can be operated either in stand-alone mode or with the included and intuitive PC software via RS-232 or USB (Windows OS required).

Key features

highly accurate thermal conductivity meter for laboratory use
wide measuring range (10 - 2.000 mW/(m*K))
wide temperature range (-50°C to 300°C)
fast, instationary resistance measurement by means of the transient hot-wire method
conforms to ASTM D7896-19 (sole instrument of ILS)
robust stainless steel sensor
no unwanted influence of convection
suitable for any type of fluid, powder or gel
requires only small sample volumes (40 ml by default, 20 ml w/ optional displacement body)
high accuracy and repeatability (+/- 1 %)
short set-up times
additional approximation of thermal diffusivity and specific heat capacity based on reference density data
thermal conductivity (λ), thermal diffusivity (aT), specific heat capacity (cp) and temperature are displayed
quick and intuitive to operate
USB/RS-232 connection to your PC for automatic measurement and temperature control
functional PC software included
optional thermostats available for automatic sample temperature control within different ranges

Easy and fast measurement

For each test only a small sample volume of 40 ml is needed (or 20 ml when using the optional displacement body). Simply immerse the probe with its platinum hot-wire into your liquid sample and LAMBDA will automatically determine the thermal conductivity in a 30-second interval.

Fields of application

This compact and highly accurate instrument opens up new possibilities for the flexible application in both laboratory and field:

Optimization of fluid development: Improve your development of HTFs, silicone oils, insulation oils, coolants etc.

Optimization of fluid applications: Solve thermal problems of your application or optimize the heat transfer in your process.

Quality control: Check the thermal conductivity of your incoming or outgoing liquids.
Fluid analysis in the field: Optimize your service and maintenance intervals.

Modes of operation

Thanks to its intuitive device menu, LAMBDA can be operated in stand-alone mode. In addition you may use a PC with the powerful LAMBDA software to set up automated conductivity tests within a desired temperature range. The captured CSV-based data can be exported easily, e.g. to EXCEL, for your further analysis.

Thermostat options for automatic sample temperature control

For sample temperature settings two different thermostats are available that are remote-controlled by the LAMBDA device. This allows for automated tests with configurable temperature ranges, increments and number of repetitions.

Dry-block thermostat (standard option, as shown below): Room temperature to 300°C
Fluid circulator w/ heat exchanger vessel for additional cooling: -35°C* to 150°C

_{* depending on chiller model and silicone oil used}

Technical data

Suitable media	fluids, gels, powders
Sample quantity	40 ml (20 ml w/ optional displacement body)
Test standard	conforms to ASTM D7896-19 (sole instrument of ILS) based on ASTM D2717
Measuring range	10 to 2.000 mW/(m*K)
Repeatability limit	1 %
Temperature range - sensor	-50°C to 300°C
Temperature accuracy	± 0,1 K
Temperature measurement	PT100
Pressure range - sensor	0 to 35 bar (optional HP version up to 500 bar available)
Measuring time	approx. 30 s
Connectivity	USB & RS-232 (PC), RS-232 (Thermostat)
Display	TFT (480 x 320 px)
Dimensions electronic unit (LxWxH)	370 x 235 x 150 mm
Weight - system	approx. 2,9 kg
Power supply	110 - 240 V AC, 50/60Hz
Energy consumption	15 W
Outer dimensions sample vessel (screw-on cup)	D = 38 mm (equals inner diameter of thermostat jacket); L = 110 mm (equals immersion depth into thermostat) see picture below
Optional accessories	Dry-block thermostat for automatic testing above RT Fluid circulator w/ extra vessel for testing below RT